No single corporate assignee dominates this dataset; the strongest concentration of related filings traces to a named inventor cluster — Losordo Thomas, Delong Dennis P and Stiles Jr Robert W — who appear together across several co-assigned families. The most-cited individual patent, covering dissolved oxygen control for aquaculture, has drawn 250 citations, making it the closest thing to a reference point that later filers build around. Beyond that cluster, ownership is fragmented across many single-filing companies, particularly in China, so 'who holds the key patents' depends heavily on which subsystem — oxygenation, filtration, or tank design — is in question.

Filing activity peaked in 2022 at 23 records and has not exceeded that level since, which points to a plateaued rather than accelerating filing curve. Because publication lags filing by roughly 18 months, the most recent one to two years in any dataset will always look lower than they eventually turn out to be, so this should not be read as an abrupt drop-off. Overall the pattern is consistent with a technology where the core claim space filled in during the late 2010s and early 2020s rather than one still in an early growth phase.

China, by a wide margin: 91 of the 171 tracked families were filed at the China receiving office, compared with 30 for the United States, 17 for WIPO/PCT filings, 13 for Europe, 7 for India and 6 for Australia. A prior-art or freedom-to-operate search limited to US and European databases will miss the majority of documented filing activity in this field, particularly around tank hardware and pipework utility models. Any competitive clearance exercise in this space should treat Chinese filings as the primary, not secondary, search target.

US20240057567A1, filed by Superior Fresh LLC and published in 2024, claims a recirculating aquaculture system built from a culture tank plus a defined set of communicating subsystems: solids control, recirculating pumping, aeration/stripping for carbon dioxide removal, pH control and oxygenation. Whether it blocks a new design depends on whether that design combines the same subsystem set in the same relationship; systems that omit one of the named subsystems, or that integrate the same functions through a materially different architecture, sit outside a literal reading of the claims. Because it is a relatively recent US publication, it is worth checking directly rather than assuming its scope from the abstract alone.

The IPC composition shows heavy concentration in animal husbandry (A01K, 158 of 171 records) and water treatment (C02F, 76 records), with separation processes, mixing equipment, microorganism-related claims and horticulture crossovers each represented in single digits. That imbalance suggests thinner coverage in areas like enzyme- or DNA-based water quality monitoring, engineered microbial communities for biofiltration, and energy-recovery pumping design — branches that touch the core RAS problem but are not yet heavily claimed. Any of these would be worth a novelty search before committing to a full filing strategy.